Condenser



June 18, 1929. J. H. WILHELM 1,717,429

CONDENSER Fild Oct. 29, 1924 2 Sheets-Sheet "l I ATTORNEY June 18, 1929. w H 1,717,429

CONDENSER Filed Oct 29, 1924 2 Sheets-Sheet 2 c- A'ITO EY- Patented June 18, 1929. v

UNITED STATES JOHN H. WILHELM, 0F ROCKAWAY BEACH, NEW YORK.

CONDENSER.

Application filed October 29, 1924. Serial No. 746,662.

This invention relates to an improved condenser,'and an object of the invention is to provide a condenser particularly adapted for use in connection with radio sets and which will be of substantial construction, neat appearance, and high efficiency.

A more detailed object is to provide a condenser of the so-called grounded rotor type, that is in which the stator plates and their immediate supporting members only are on one side and all other parts of the device are on the other side of the circuit, to construct the parts so that Wide air spaces occur between the metallic members of the two sides, also so that only a small amount of insulating material is required and a correspondingly low loss is secured, to provide a single bearing for the rotor of such a type as to firmly support the rotor and frictionally retard any objectionable rotary movement thereof while yet allowing free and easy rotary movement through the medium of the usual operating dial, and to arrange parts of the device so that the rotor bearing, and the elements on which it is formed and upon which the stator supports are carried comprise a suitable expanse of conductive material interposed between the rotor and stator plates and the operating dial to prevent likelihood of interference due to the so-called body capacity, when an operator is manipulating the dial.

A further object is to so construct the device as to provide an efiicienemeans whereby to adjust one set of plates relative to the other.

A further object is to provide improved means to retain the stator plates, and the rotor plates connected with their respective supporting elements.

Other objects and aims of the invention, more or'less specific than those referred to above, will be inpart obvious and in part pointed out in the course of the following description of the elements, combinations, ar-

" rangements of parts and applications of principles constituting the invention, and the scope of protection contemplated will be indicated in the appended claims.

In the accompanying drawings which are to be taken as a part of this specification, and in which I have shown merely a preferred form of embodiment of the invention Fig. 1 is a side elevational view of a condenser constructed in accordance with this invention.

Fig. 2 is a fragmentary detail view illustrating the means for adjusting one set of plates relative to the other.

Fig. 3 is a vertical central sectional view, partially in elevation, of the structure shown in Fig. 1 and showinrr the same as it appears mounted upon a suitable panel board, and

Fig. 4 is a detail sectional view taken upon the plane of line IVIV of Fig. 3 for illustrating the manner in which the plates are fixed upon their supporting elements.

Referring to the drawings for describing in detail the structure therein illustrated the reference character L indicates What may be termed a base plate or member upon which the other elements of the condenser are mounted. This base plate is intended to be fixed to the rear side of a suitable panel board G by any suitable means, as for instance by belts or the like extending through openings 1 provided in said base plate.

The base plate is of conductive material and is preferably of circular form. It may conveniently be formed of sheet metal, and is provided with a flange as 2 at its periphery for extending into engagement with the surface of the panel board and holding the main portion as 3 of the plate spaced away from the panel board. 7

The main portion 3 has a large opening 4 formed centrally therethrough to provide a large bearing for the rotor.

The rotor comprises an operating shaft 5 to the inner end portion of which the rotor plates 6 are connected and to the outer end portion of which is connected the control dial H.

Within the opening 4 the shaft 5 has a disk 7 fixed thereto and the peripheral portion of this disk is shaped to provide a ball race 8. The inner circumferential surface of the walls of the opening 4 in the part 3 of plate L is likewise shaped to provide a ball race as 9, the races 8 and 9 being in opposed relation and adapted to contain a suitable number of balls 10 therebetween.

The large diameter of the bearing thus afforded between the rotor and the plate L serves to .provide the necessary amount of friction for preventing likelihood of unintentional rotation of the rotor at any time, and yet the character of the bearing provides for an easy and smooth rotation of the rotor with slight manual effort applied to the dial handle H.

A suitable ball retainer and spacin element as 11 may be provided if desirei and where this element is employed it may conveniently extend loosely into an annular pocket or groove as 12 provided in the seat or race 8 so that said retainer may rotate freely relative to the disk 7.

It is desired to note that during any rotation of the disk 7 within the race or bearing 9 there will be an accompanying rotation and rolling motion of the balls along the race ways, and there will likewise be an accompanying rotation of the ball retainer 11 within the groove 12. The engagement of the retainer with the walls of the groove will generate an additional amount of soft, frictional resistance against the free rotation of the balls, and this resistance may be increased in quantity to any appropriate extent by making the groove 12 of relatively greater depth with a'corresponding increase in depth of the ball retaining member. I

The disk 7 is of conductive'material and for convenience in manufacture is preferably formed of two pieces as 13 and 14 of sheet metal laid flat against each other and having their peripheral portions suitably shaped to provide between them the race way 8 and the groove 12. They may be held together and in position upon the shaft 5 by any appropriate means but preferably are clamped in positionby means of a nut 15 threaded upon said shaft and arranged to clampthem against a suitable opposing shoulder 16 provided on the shaft.

The race way 9 may for convenience also be formed of two separate elements one, as 17, being a part ofthe main portion 3 of the plate L and the other, as 18, being a part of a separate plate as 19 which to the portion 3 by any suitable means.

The rotor plates as 6-6 may be connected upon the inner end of shaft 5 1n any suitable manner but it is a feature of the present invention to provide an improved method of attachment for said plates and to this end the drawings herewith illustrate the shaft as being provided with a sleeve 20 fitting closely about the. shaft, said sleeve and shaft being both metallic and having a plurality of mating slits as 21 and 22 therein respectively.

The rotor plates 6 extend into said slits anda clamp nut as 23 which is threaded upon the extending portion 24 of the shaft, and which bears upon the adjacent end surface 25 of the sleeve, holds the sleeve and shaft in such relation that the plates are clamped rigidly between the opposing faces of said slits.

There are as many pairs of slits as the number of plates it is desired the rotor shall carry. The plates are all of the same thiclmess and the slits of each pair bear the same relation to each other so that it is simply necessary to place the plates in their respective pairs of slits and then tighten the nut 23, which will simultaneously clamp all of the plates in J rigid position.

As a convenient and efficient means for providing positive electrical communication from an appropriate binding post as 26 on the base plate L to the rotor the drawing illustrates the use of a-so-called pig tail connector 27. The inner convolution as 28 of this connector is fixed to a tongue 29 which is formed as a part of a Washer-like member 30 which surrounds the shaft 5 and which is clamped between the shoulder 16 and the bearing disk 7 The outer convolution as 31 is connected with a stationary arm as 32 which extends radially from adjacent the shaft 5 across the surface of the bearing disk 7 and has its outer end clamped to the binding post 26 by means of a suitable clamp nut 33. 7

Appropriate stops as 34 and 35 are provided upon the plate L standing in the path of a cooperative stop 36 on the bearing disk 7 so as to limit the rotary motions of the rotor in both directions and thus not only assure proper functioning of the condenser but also prevent the imposition of any undue strains upon the pig tail connector.

The stator plates as 3737 may be mounted in any appropriate manner but as hereinabove mentioned it is a feature of this invention to provide an improved form of mounting for said plates. As indicated in the drawings these plates are supported upon two metallic standards as 38 and 39 spaced apart at different circumferential points upon the plate L.

The plates are rigidly connected with these standards and the standards are adjustably connected with the base plate L.

The manner of connecting the plates with the standards is similar-to the manner of connecting the rotor plates to the shaft 5. As illustrated the standards are hollow so that they comprise sleeves into each of which is fitted a slidable core piece 40. The sleeves and core pieces are provided with mating slits 41 and 42 respectively, corresponding to the slits 21 and 22, and a clamp nut as 43, corresponding to the clamp nut 23, is provided for engaging threaded extensions 44 of the core pieces to cause the opposing surfaces of the sllts to grip and hold the stator plates.

The manner of adjustably connecting the standards with the base plate consists in fixing to the forward end of each-standard a cross member as 45 of insulating material and of in turn connecting these cross pieces with the base plate by means of adjusting screws 46 two for each cross member and disposed at opposite sides of the respective standards and spaced appreciable distances therefrom. a

The adjusting screws 46 extend through apertures 47 provided in the end portions of the cross members 45, and opposing parts, as heads 48 and nuts 49, serve to prevent any longitudinal movement of said screws the other end of the j er as here in through the cross members. The forward ends of the screws extend through apertures in the main portion 3 of the plate L and 1 suitable clamp nuts as 51 and 52 engage the screw at opposite surfaces of the portion 3 so that rotary adjustment of said nuts upon the screws will produce longitudinal movcl ment of the screws and a consequent adjustment of the respective ends of the cross members with respect to the portion 3.

The two standards 38 and 39 are arranged at points which are nearly diametrically opposite each other across the centre of the rotor shaft, and the cross members 45 each extend longitudinally in directions transverse to a straight line between the two standards, and b it will be seen therefore that adjustment of the distance of the opposite ends of the two cross members 45 to or away from the base portion 3 stator plates carried by the standards so as to bring said plates into proper coogeratlve relationship with the rotor plates. y moving both ends of one cross member together toward or away from the base part 3 the longitudinal plane of the group of stator plates will be brought into or out of parallelism with the surface plane of the base portion 3, while by adjusting one end 'of a cross member toward or away from the base portion 3 Without accompanying adjustment of same cross member will change the angle of the standards relative to the base and resultin a certain twisting of the group of stator plates, either into or out of exact parallelism with the surface? plane of the base portion 3. By these means it will be seen that the stator plates may be adjusted either bodily toward or away from the base member, or one end of the group may be moved toward or away from the base memher, or the group may be bent or twisted, all as may be required to bring the group of stator plates into the most accurate possible relationship to the group of rotor plates. The slight inaccuracies which the manufacture of large numbers of these condensers are bound to occasion in the mounting of the rotor plates may be readily corrected by adjustment of the stator plates, and in this way it has been found possible to place the several plates of the two groups considerably closer together than would otherwise be practical.

The various parts comprising the condenssimple form and may be cheaply produced.

They may be quickly and easily assembled by relatively unskilled labor, and then after assembly the bank or group of stator plates may be adjusted into proper relationship with the rotor plates by a single skilled operator, and a very high grade condenser may be thus produced at comparatively small cost.

s many changes could be made in this will be effective in adjusting the 1 shown and described are of I construction without departing from the scope of the invention as defined in the folowing claims, it is intended that all matter contained in the above. description or shown in the accompanying drawings, shall be interpreted as illustrative only and not in a imiting sense.

If desired suitable friction washers as 53 and 54 of felt or other suitable material may be arranged within the groove 12 between the 7 ball retainer 11' and the walls of said groove as a means to increase the friction against relative movement of the ballretainer around the groove.

The balls 10 are retained in position by eing engaged between the two opposed V- shaped ball races and it is impossible for them to become displaced. To provide for assembly and disassembly one or both of the all races must'be separable and since each 8 of these ball races as shown are formed of two separate plates such separation may be readily accomplished. In the instance illustrated the two plates 13 and 14 which constitute the disk 7 and which are held in position by the clamp nut 15, will separate upon removal of said nut, and in this connection it is noted that not only does the two-plate structure of disk 7, and the manner of retaining them assembled, provide for the easy 9 assembly and disassembly of the bearing parts, but said two plates being of sheet metal and being clamped firmly together only at their central portions have their marginal portions resilient and yieldable relative to each other. In the instance illustrated this spring characteristic of the plates is taken advantage of as an additional means to provide for unintentional rotation of-the rotor by making the annular portions of said two disks which comprise the V-sliaped groove at the periphery of the disk of such diameter that they always pressas springs against the balls and hold the balls against the walls of the opposing V-shaped groove in the portion 3. The portions of .the plates radially outwardly from the center are sprung apart bythis engagement against the balls and a certain yielding tension is thereby always maintained between the balls and the opposing races which will prevent likelihood of any unintentional rotation of the rotor even without necessity for counterbalancing the rotor in any Way.

Having thus described my invention, what claim as new and desire to secure by Letters Patent is 1. An instrument comprising a base plate having a relatively large bearing opening therethrough, a relatively small shaft extending through said bearing opening having a disk fixed thereto extending radially therefrom, the peripheral portion of said disk being shaped to provide a ball race, the walls of said bearing opening being shaped 3 isaid base plate adapted to have co-operative relationship .upon rotation of said shaft.

2. Aninstrument comprising a base plate having a relatively large bearing opening therethrough, a relatively small shaft extending through said bearing opening having a disk fixed thereto extending radially therefrom, the peripheral portion of said disk being shaped to provide a ball race, thewalls of said bearing opening being shaped to provide an opposing ball race, balls arranged between said two ball races whereby to provide K rotary engagement of the disk within said bearing opening adapted to constitute the sole supporting means for said shaft by which said shaft is rotatably mounted, the race way of said diskhaving an annular groove therein, a member engaging within said groove having frictional engagement with the walls thereof to oppose movement of said member circumferentially along said groove, said member also having engagement with said balls to thereby retard rolling movement of said balls along said race ways for the purpose set forth, and parts carried by said shaftand said base plate adapted to have cooperative relationship upon rotation of said shaft.

3. An instrument comprising a base plate having'abearing opening therethrough, a shaft extending through said bearing opening and having a shoulder thereon, the wall of said opening being constructed to provide a V-shaped ball race, two members carried by the shaft constructed to provide between them an opposing V-shaped ball race, means to clamp said two members together and against the shoulder of the shaft to thereby fix said members upon the shaft, balls arranged being a disk fixed thereto extending radially 1 therefrom, the peripheral portion of said disk being shaped to provide a ball race, the walls of said bearing opening being shaped toprovide an opposing ball race, balls arranged between said two ball races whereby to provide rotary engagement of the disk within said bearing opening adapted to constitute the sole supporting means for said shaft by which said shaft is rotatably mounted, one of said race ways having an annular groove therein, a ball retarding device engaging within said groove and having engagement with said balls to oppose movement of the balls along the race ways, friction means arranged within said groove engaged by said ballretarding device to frictionally oppose movement of said ball retarding device, for the purpose set forth, and parts carried by said shaft and by said base plate adapted to have cooperative relationship upon rotation of said shaft.

5.- A friction bearing for rotating shafts, comprising a relatively stationary part through a bearing opening of which the shaft projects, the walls of said bearing opening being formed to provide a V-shaped ball race, a pair of plates carried by said shaft pr0jecting radially therethrough being fixed by their central portions to said shaft and having annular peripheral portions shaped to provide collectively a V-shaped ball race in opposition to the first ball race, balls arranged between said opposing ball races and engaging therewith, and the plates comprising a second ball race being resilient and the annular marginal portions thereof being arranged to exert spring pressure against the balls to hold said balls pressed at all times against the other ball race.

In testimony whereof I affix my signature.

JOHN H. \VILHELM. 

